In hydronic heating and cooling systems, a balanced system is required to assure proper fluid flow to heating/cooling terminals. A good system design requires the ability to isolate equipment for repair and also provides check valves to prevent unwanted flow in the wrong direction. Typical applications include zoned pumping, parallel pumping, and standby pumping. On smaller systems, where these functions are still necessary, present solutions require multiple different valves that must be separately installed, and can be cost-prohibitive. As a cost alternative, installers may choose a less expensive option of a standard off-the-shelf ball valve with extremely limited balancing ability to assemble the system. The valve is closed to an estimated position in order to control flow rate for the purpose of balancing. This technique is not accurate and does not provide optimum flow rate for the purpose of balancing, which results in higher than needed energy costs and sacrificed comfort.
For those installations where proper flow to terminal units is critical, the installer or balancing contractor requires an accurate method to balance the system. Balancing and flow measurement can be accomplished in several ways by using a calibrated ball valve, venturi, flow meter, or other similar device. A balanced system provides better heat and results in energy savings.
A properly installed heating system also includes flow control, or check, valves to prevent gravity flow. Without flow control valves, uncontrollable heating of zones in a building can occur. With flow control valves, when the circulating pump is off, the flow control valves are closed, preventing unwanted hot water from flowing backward. When the pump turns on, the pressure developed by the pump unseats each flow control valve and allows water to flow past the valve. Additionally, the flow control valves prevent gravity flow and prevent the system fluid from flowing in the wrong or unwanted direction, which can damage the pump and other equipment in the system.
There exists a need to provide valve that provides flow control to prevent unwanted backflow, and includes a flow meter and throttling/isolation valve to accurately balance flow through the valve and to shut off flow through the system.